Study on Geotechnical aspects related to rehabilitation of deteriorated sewer pipelines

与修复劣化污水管道相关的岩土工程研究

• 批准号: 15360257
• 负责人: TOHDA Jun
• 金额: $ 5.76万
• 依托单位: Osaka City University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2006
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-15360257/
• 关键词: Sewer Pipeline; Backfill Soil; Deformation Modulus; Time History; Repeated Vehicle Load; Deflection Ratio; Plastic Pipe; Soil-structure Interaction; 乾湿繰返し; たわみ性管; 老朽管; 復旧; 空洞; 長期挙動; 剛性

In Japan, many old sewer pipelines installed in urban areas were severely deteriorated to decrease their functions and increase the possibility of ground depression. Sewer pipes are not pressure pipes. If the old pipes are deteriorated, therefore, soil particles tend to flow into the pipes with water, easily developing voids in the ground to cause ground depression. However, mechanism and actual condition of void development in the ground have not been clarified yet. Also, since excavation for replacing the deteriorated pipes by new pipes is difficult in urban areas, no-dig rehabilitation methods using plastic inner liners have been developed and are increasingly being used in the world. The plastic inner liners have long lives, but their rigidity decreases according to the elapsed time due to relaxation. On the contrary, the rigidity of backfill soils around the pipes increases according to the elapsed time. Therefore, mechanical behavior of buried pipes that is governed by relative rigidity between soil and pipe will be changed according to the elapsed time. However, this problem has not been studied hitherto.This study was carried out to clarify mechanism of void development in the ground around deteriorated old sewer pipelines and to investigate long-term change in soil-structure interaction. The main conclusions can be summarized as follows:1) Inflow of soil through opening at joints of the pipeline develop the voids in the ground. The location of the voids is at the upper part of the pipe, but not at the top of the pipe. Cracks along the long axis of the pipe do not produce the voids in the ground.2) Apparent rigidity of backfill soils decrease due to repeated vehicle loading, resulting in increase in deflection of plastic pipes. The relaxation of plastic pipes during the elapsed time remarkably strengthens the deflection of plastic pipes.

在日本，许多旧的下水管道安装在城市地区严重恶化，降低其功能，并增加地面凹陷的可能性。下水道管道不是压力管道。因此，如果旧管道损坏，土壤颗粒倾向于随水流入管道，容易在地面上形成空隙，导致地面凹陷。然而，关于地基中空洞形成的机理和实际条件，至今还没有明确的认识。此外，由于在城市地区用新管道替换损坏的管道的挖掘是困难的，因此开发了使用塑料内衬的非挖掘修复方法，并且在世界上越来越多地使用。塑料内衬具有长寿命，但由于松弛，其刚度会随着时间的推移而降低。相反，管道周围回填土的刚度随着时间的推移而增加。因此，埋地管道的力学行为将随着时间的推移而发生变化，而这种变化是由土与管道之间的相对刚度决定的。然而，这个问题还没有被研究到目前为止，本研究进行了澄清，在恶化的旧下水管道周围的地面空洞的发展机制，并调查长期变化的土-结构相互作用。主要结论如下：（1）通过管道接头处开孔流入的土在地面上形成空洞。空隙的位置位于管道的上部，而不是管道的顶部。沿着管道长轴方向的裂缝不会在地面产生空洞。2）由于反复的车辆荷载，回填土的表观刚度降低，导致塑料管道的挠度增加。塑料管在经过一段时间后的松弛显著地加强了塑料管的挠度。

项目成果

地中空洞充填用注入管及びこれを用いた地中空洞充填方法

用于填充地下洞穴的注入管以及使用该注入管填充地下洞穴的方法

• 发表时间: 2003